Process for preparing a catalytic composition for the hydroconversion of petroleum fractions

ABSTRACT

The invention relates to a method of preparing a catalytic composition comprising at least one non-noble metal from group VIII and at least one metal from group VIB of the periodic table. The invention also relates to the catalytic composition thus produced, which has a high specific activity in reactions involving the hydroprocessing of light and intermediate fractions, preferably in reactions involving the hydrotreatment of hydrocarbon streams, including hydrodesulphurization (HDS), hydrodenitrogenation (HDN) and hydro-dearomatization (HDA).

TECHNICAL FIELD OF THE INVENTION

This invention is related to a process for preparing a catalyticcomposition that is made up of at least one Group VIII non-noble metaland at least one Group VIB metal in the periodic table. The catalyticcomposition, also an object of this invention, presents a high specificactivity in light and intermediate fraction hydroprocessing reactions,preferably in hydrotreatment reactions of hydrocarbon streams, amongstwhich can be found hydrodesulfurization (HDS), hydrodenitrogenation(HDN), and hydrodearomatization (HDA).

BACKGROUND OF THE INVENTION

Environmental protection government agencies demand more and more fuelswith a lower content of precursor components to atmosphericcontamination such as sulfur and nitrogen, and low contents of nickeland vanadium metals, among others. In addition, in order to take maximumadvantage of the oil reserves, it is necessary to process heavier andheavier loads, and the content of said pollutants is increased in thefuels produced; therefore, it is necessary to develop new catalyticprocesses and materials that eliminate these pollutants from thehydrocarbons or fossil fuels in a more efficient manner, in order tominimize the gaseous emissions polluting the atmosphere, and thus complywith the ecological regulations that are becoming more and more strict.

The most efficient industrial processes for the removal of fossil fuelpollutants are the hydroconversion processes which are applied topractically all fractions of petroleum such as: gasoline, diesel,feedstock for catalytic cracking (FCC), and intermediate distillates.For the specific case of this invention, light and intermediatepetroleum fractions are considered to be those that make up hydrocarbonswhose boiling points are equal to or less than 180° C., and intermediatepetroleum fractions that make up hydrocarbons whose boiling points areequal to or greater than 180.1° C. and less than or equal to 400° C.

In the hydroconversion processes, the light and intermediate petroleumfractions are hydrotreated and/or hydrodcracked in the presence ofhydrogen. The hydroconversion processes include all of the processes inwhich a fraction of hydrocarbons reacts with hydrogen at hightemperature and pressure, such as: hydrogenation, hydrodesulfurization,hydrodenitrogenation, hydrodemetalization, hydrodearomatization,hydroisomerization, and hydrocracking.

Likewise, the catalysts that are used are mainly made up of at least oneGroup VIII non-noble metal and at least one Group VIB metallic componentin the periodic table, deposited on a high specific surface area supportmade up of metallic oxides such as alumina, silica, titania, and/ortheir blends, optionally containing secondary promoters or additivessuch as halogens, phosphorus, boron, etc. The catalysts are generallyprepared by impregnation of the support with aqueous solutionscontaining the metal compounds in question followed by drying andcalcination procedures. The catalyst preparation procedures forhydroprocessing have been addressed in the American U.S. Pat. No.5,089,462 and U.S. Pat. No. 2,853,257, and the European patents EP0,448,117 and EP 0,469,675.

The commonly used supports are based on a refractory material made up ofalumina. The molybdenum-alumina catalysts promoted with cobalt are usedpreferably when the process required is that of hydrodesulfurization,while the molybdenum-alumina catalysts promoted with nickel are widelyused when, in addition to hydrodesulfurization, hydrodenitrogenation andhydrogenating aromatics (hydrodearomatization), are required in thefraction that must be hydroprocessed due to the high hydrogenatingactivity inherent to the nickel.

The most relevant advances that have been achieved recently with respectto catalysts for hydrodesulfurization and hydrodenitrogenation, and incatalysts for hydroprocessing in general, are based on cobalt or nickelmolybdenum-tungsten unsupported phases (U.S. Pat. No. 6,534,437, U.S.Pat. No. 6,582,590). These bulk catalysts of Ni—Mo—W—O or Co—Mo—W—O,present high specific areas made up between 100 and 200 m²/g. Thehydrodesulfurizing activity of these catalysts was measured with amolecule model of dibenzothiophene (DBT). These catalysts present aspecific activity in [molecules/g*s] superior to the activity of theconventional catalysts supported on alumina. These catalysts present ahigh density, so a greater quantity of material fits into one unit ofreactor volume. Thus, the activity measured with respect to thecatalyst's volume turns out to be around four times higher compared tothe commercially available conventional catalysts of nickel-molybdenumsupported on alumina.

The synthesis of unsupported catalysts based on metals from Groups VIIIand VIB in the periodic table has been carried out previously, (Catal.Lett. 10 (1991)181; J. Thermal Anal. 40 (1993) 1253). These catalystshave generally been focused toward the oxidation of hydrocarbons, forexample, oxidative propane dehydrogenation and/or the partial oxidationof propylene into acrolein and acrylic acid. The ammonia phaseprecipitation from NiMoO₄.mNH₃,nH₂O is known. This precipitationprocedure has been applied recently to the preparation of catalysts forhydrodesulfuration and hydrotreatment of different petroleum fractions.

To date, the proposed structure for the precipitate formed from theammonia complex is an ammonium nickel molybdate phase with ahydrotalcite-like structure which corresponds to the stoichiometricformula (NH₄)HNi₂(OH)₂(MoO₄)₂. This material presents a laminarstructure that contains the molybdate anions in the interlaminar regionsbonded with nickel hydroxide laminae. The procedure used for thesynthesis of this type of materials is described in Appl. Catal. 72,321-329 (1991) and Solid State Ionics 63-65 (1993) 731-35.

In the American U.S. Pat. No. 6,156,696B and U.S. Pat. No. 6,162,350B,procedures for the preparation of a catalytic composition, which is madeup of at least one Group VIII non-noble metal that can be nickel orcobalt, and at least two Group VIB metals, which can be molybdenum andtungsten, are described. The general formula described is(X)_(b)(MO)_(c)(W)_(d)O_(z), where x is a Group VIII non-noble metal (Nior Co) and the molar ratio b/(c+d) takes values of 0.5 to 3, andz=[2b+6(c+d)]2. These materials present an x-ray diffraction patterncharacteristic of an amorphous material, with very wide peaks at adistance of 2.53 and 1.7 angstroms. The substitution of molybdenum atomsfor tungsten atoms in the material allows it to obtain an amorphous ormicrocrystalline structure that upon being calcined crystallizes into aunknown structure and that is characterized because it presents adiffraction peak of 53.82° at position 2-theta, with a width halfway upthe peak that goes from 1.3 to 1.7°. In order to achieve an optimalyield in the precipitation of the salts used, it is necessary that atleast one of the salts be partially dissolved during the precipitation.The catalysts obtained are mixed with alumina and extruded, presentinghigh hydrodesulfuration and hydrodenitrogenation activity inhydrotreatment reactions from different petroleum fractions.

Another strategy that has been employed for the synthesis of bulkcatalysts for hydrodesulfuration is through the thermal decomposition ofammonium thiometallate. U.S. Pat. No. 4,243,554 claims molybdenumdisulfide catalysts promoted with cobalt and nickel with high specificarea that can be obtained through the thermal decomposition of severalthiomolybdate ammonium salts that have the formula(NH₄)₂[MoO_(x)S_(4-x)], where x is 2. The decomposition of the thiosaltsoccurs in the presence of a hydrocarbon solution that contains sulfurcompounds with a high pressure of hydrogen and at temperatures between300 and 800° C.

On the other hand, the decomposition of these salts in the presence of ahydrocarbon generates a kind of molybdenum sulfide based catalystcontaining carbon, which, in some manner, turns out to be responsiblefor the generation of active sites and for the high hydrodesulfuratingactivity of these materials (Berhault et. al. J. Catal. 198, 9-19(2001)). U.S. Pat. No. 4,508,847 reveals a catalytic composition ofMoS_(2-x)C_(z) where z is the carbon content and varies between0.01<z<3, and x is the sulfur content and varies between 0.01<x<0.5.This catalyst is obtained through the exposure of a molybdenum precursorsuch as ammonium thiomolybdate or ammonium thiotungstate; ammoniummolybdate or ammonium tungstate—thiomolybdates, molybdates,thiotungstates, ammonium tungstate substitutes—with a stream composed ofsulfur, hydrogen, and hydrocarbons at temperatures between 150 and 600°C. The catalysts present high specific surface areas and can be promotedwith other metals like cobalt and/or nickel to produce high-activitycatalysts in hydrotreatment reactions, higher than the catalysts withsimilar metals supported on alumina. However, in the procedure describedin this patent, the main source of carbon comes from the carbonizationof the hydrocarbon present during the precursor's decomposition.

The addition of an organic compound as a carbon source to the inorganicmolybdenum salts, or the direct sulfiding of organic salts frommolybdenum, not only promotes the formation of metal carbide sulfidespecies, such as MoS_(x)C_(z), but also favors the complete sulfiding ofmolybdenum to MoS₂, which can generate a greater density of active sitesin the catalyst (Farag H. Energy & Fuel, 16 (2002) 944-950). Such is thecase in U.S. Pat. No. 4,528,089 and U.S. Pat. No. 4,650,563 that reveala procedure for obtaining a molybdenum disulfide catalyst containingcarbon that consists of the thermal treatment of a precursor salt in thepresence of sulfur and under oxygen-free conditions. The precursor salthas a general formula of ML(Mo_(x)W_(1-x)S₄) where M is one or moredivalent promoter metals, such as Ni, Co, Zn, Cu, or a mixture of them;x varies between 0 and 1; and L is one or more neutral organic complexesthat can act as chelating polydentate ligands that contain nitrogen. Thecatalysts obtained this way present high activity in hydrotreatmentreactions, superior to the catalysts obtained with conventionalprecursors such as cobalt-molybdenum on alumina, even when theirspecific area did not turn out very high.

U.S. Pat. Nos. 4,581,125 and 4,514,517 refer to a molybdenum disulfidecatalyst that is obtained through the thermal decomposition of aprecursor salt that contains carbon that can be (NR₄)₂[M(WS₄)₂] or(NR₄)_(x)[M(MoS₄)₂]. The thermal decomposition occurs in an oxygen-Freeatmosphere in the presence of sulfur and hydrogen at a temperaturegreater than 150° C. The (NR₄) group contains carbon, and is an ammoniumcation substitute where R can be an alkyl or an aryl group. M is themetal promoter and is in close interaction through covalent bonds withthe anion (MoS₄)⁼ or y(WS₄)⁼, and can be nickel, cobalt, or iron; x is 2if M is nickel, and y is 3 if M is cobalt or iron. Ideally, the catalystshould be formed in the presence of hydrocarbons in order to obtain itsmaximum catalytic performance. In order to increase the specific area ofthe catalysts obtained from the thiosalt decomposition, U.S. Pat. No.6,156,693 describes a hydrothermal treatment procedure for the ammoniumtetrathiomolybdate precursor salt, which is dissolved in a solvent witha high boiling point and water under hydrogen pressure at temperaturesbetween 350 and 400° C. The presence of water is effective for thegeneration of active sites; however, this should be eliminated after theammonium tetrathiomolybdate decomposition in order to give way for amore active MoS₂ catalyst.

Patent US 2005/0059545 A1 describes a procedure for obtaining molybdenumsulfide-based catalysts and/or tungsten-based catalysts containingcarbon through a hydrothermal procedure. This procedure consists intreating an ammonium tetrathiomolybdate precursor salt, A_(x)MoS₄, whereA is the ammonium ion, a tetraalkylammonium ion (x=2), or a diamine ion(x=1) in the presence of a promoter salt that can be nickel, cobalt,iron, or ruthenium, under hydrothermal conditions. The catalystobtained, Ni/CoMoS_(2-x)C_(x), where x takes values from 0 to 1, isactivated in atmosphere of H₂S/H₂ at high temperature before thehydrodesulfuration reaction.

The incorporation of an organic additive, such as a chelate complex oran organometallic complex into the impregnation solutions of thehydrodesulfurization catalysts supported on alumina promotes an optimalsulfiding of the active metallic components and a maximum promotion ofthe molybdenum disulfide, favoring their dispersion and creating a highdensity of active sites, with which an increase in the catalyticactivity in hydrotreatment reactions has been achieved.

U.S. Pat. No. 6,566,296B2 refers to a catalytic composition compound ofMoO₃ in concentrations of 10 to 30 wt. %, WO₃ in concentrations between30 and 50 wt. %, NiO in concentrations between 30 and 50 wt. %, andAl₂O₃ in concentrations between 0 and 20 wt. %. The catalyticcomposition is prepared via the coprecipitation method in the salts inwhich at least one of the salts remains in solid state or partiallydissolved; afterward, they are mixed with an alumina to form extrudes.The extrudes obtained are impregnated with an organic compound such asdiethylene glycol, or an amino group substitute, NR₄, where R cancontain up to 10 carbon atoms. Other additives that can be used as asource of carbon in the impregnation of the extrudes are glycols,saccharin, polysaccharides, and ethylenediamine tetraacetic acid (EDTA).With this strategy of incorporation of an organic compound as a sourceof carbon, a considerable increase in the catalytic activity of thesecatalysts is achieved in hydrotreatment reactions.

The addition of tungsten to the bulk catalysts of hydrodesulfurationfavors their catalytic activity in comparison to the catalysts that onlycontain molybdenum, U.S. Pat. No. 6,534,437. The average bulk density ofthese catalysts is much greater than that of the conventional catalysts,which is why a greater quantity of catalytic material is required tofill a volume of a given reactor. In the case of bulk catalysts, thecost of the catalysts increases considerably, which is why newalternatives for the substitution of the molybdenum atoms by other lessdense metals, such as chromium, and manganese (U.S. Pat. No.6,635,599B1, U.S. Pat. No. 6,783,663 B1) have been sought.

There is a range of catalysts for hydrotreatment reactions, bothsupported and unsupported, whose main phases are basically made up ofcobalt, nickel, iron, molybdenum, and tungsten metals in their sulfidedphases. However, there is also a need to supply more efficient catalyticsystems in order to eliminate or reduce the level of pollutants infuels. In this invention, a procedure for obtaining a catalyticcomposition of at least one Group VIII non-noble metal and at least oneGroup VIB metal and which, in addition, contains carbon generated by theaddition of an organic compound during synthesis that favors sulfidingand catalytic activity in hydrotreatment reactions, is proposed.

The process and catalyst that are the object of this invention are usedin hydrotreatment reactions that involve hydrodesulfuration,hydrodenitrogenation, and aromatic hydrogenation because these catalystsare used in the petroleum refining processes for the production of cleanfuels, the elimination of sulfur and nitrogen in different hydrocarbonfractions and cuts, and for reducing the content of aromatics in fuels.They can also be employed in the hydrotreatment of heavy fractions likevacuum residue and heavy crudes.

SPECIFICATION OF THE INVENTION

This invention is related to a new, highly active, catalytic compositionfor hydroconversion reactions of different hydrocarbon fractionscontained in petroleum, preferably for the hydrodesulfuration,hydrodenitrogenation, and aromatic hydrogenation reactions. The catalystthat is the subject of this invention consists of at least one GroupVIII non-noble metallic element, at least one element from Group VIB,and one organic component as a carbon precursor, in close interactionwith the active metallic phases.

Therefore, one of the goals of this invention is to obtain a catalyticcomposition basically made up of at least one Group VIB metal, from aprecursor salt that can by molybdenum or tungsten, preferablymolybdenum; soluble in a polar solvent; made up of at least one GroupVIII non-noble metal, from a cobalt, nickel, iron, or rutheniumprecursor salt, preferably nickel and/or cobalt; and made up of anorganic compound as a carbon precursor that can be a surface activeagent, such as an ionic, cationic, anionic, or neutral surfactant, or aquaternary salt from substituted ammonium (NR₄ ⁺) where R can be analkyl or aryl group composed of 1 to 8 carbons in the alkyl chain.

Another goal of this invention is to establish the procedure forobtaining catalysts, which consists in the complete solution of theprecursor salts in a polar solvent, such as water, maintaining asolution pH between 5 and 14 through the addition of a base, which canbe ammonium hydroxide, ammonium carbonate, or a hydroxide of aquaternary ammonium salt such as tetrabutyl ammonium hydroxide. Once thecompletely soluble complex is formed, an organic compound is added, inthe event that the base used was not the quaternary ammonium hydroxide,which consists of a surface active agent, such as an ionic, anionic,cationic, or neutral surfactant. Afterward, the complex is crystallizedthrough the evaporation of the excess solvent, thus obtaining a GroupVIB mixed metal oxy-hydroxide and a Group VIII metal containing carbonor an organic compound.

Another goal of this invention is the thermal treatment procedure towhich the material obtained must be subjected, which, under nocircumstance should be subjected to oxidant gaseous atmospheres attemperatures higher than 200° C. Said procedure consists in thermaltreatment at temperatures comprised between 200 and 1000° C. in an inertgas flow such as nitrogen, helium, or argon in which a nickel molybdenummixed oxide containing carbon or a nickel molybdate containing carbon isobtained, in the event that the metals selected are molybdenum andnickel; or a cobalt molybdate, cobalt molybdenum mixed oxide containingcarbon, in the event that the metals selected are molybdenum and cobalt;or a nickel mixed oxide, cobalt, and molybdenum or mixed molybdate ofnickel and cobalt, in the event that two Group VIII metallic componentsare selected, and molybdenum.

Another goal of this invention is the sulfiding procedure for obtainingthe sulfided form of the catalysts that consists of the exposure of thedry material and or material thermally treated in inert atmosphere at atemperature comprised between 200 and 600° C., in an H₂S flow dilutedbetween 0.5 and 30% in hydrogen volume. Another method consists in thedirect exposure of the dry material, cobalt-nickel molybdenumoxy-hydroxide, or the thermally treated material, nickel molybdate orcobalt molybdate or nickel and cobalt molybdate, to a hydrocarbon liquidstream containing sulfur-containing organic compounds enriched withdimethyl disulfide (DMDS) at a concentration comprised between 0.1 and 5wt. % of sulfur, at a temperature comprised between 200 and 600° C. anda hydrogen pressure comprised between 1 and 100 Kg/cm². Through thisprocedure, the oxidized phases of the active components are convertedinto the active sulfide phases. The presence of carbon favors thesulfiding, the promotion of molybdenum disulfide, and the formation of ahigh surface concentration of active species.

The active species included in this invention consist of sulfided phasesof at least one Group VIII non-noble metal and of at least one Group VIBmetal containing carbon.

Another aim of this invention is that the catalytic composition, also agoal of this invention, can be integrated or contain an inorganicmaterial, such as binding material, for the formulation of extrudes,which can be alumina, titania, zirconia, silica, or a mixture of them,in a proportion comprised between 0 and 50% in weight as an oxide of thecorresponding metal, taking the total of the oxides present as a base.

One more aim of this invention is to obtain a catalyst in extrude formwith compact bulk density similar to that of the conventional catalystssupported through the integration of a low density binding material forthe formulation of extrudes.

Another goal of this invention includes a hydrocarbon fractionhydrotreatment process, where the catalysts are used in their sulfidedphase in contact with a liquid load of the hydrocarbon fraction undertypical hydrotreatment conditions.

BRIEF DETAILED DESCRIPTION OF THE DRAWINGS

For the purpose of obtaining an understanding of the catalyticcomposition for petroleum fraction hydroconversion, reference will bemade to the figures that are included:

FIG. 1 indicates an x-ray diffraction pattern referred to in Example 1,characteristic of the catalytic composition in its dry phase (a),thermally treated, the same that corresponds to a mixture of the nickelmolybdate beta and alfa phases (b) and in its sulfided phase (c) thatpresents the peaks characteristic of a mixture of Group VIII and GroupVIB sulfide metals, object of this invention.

FIG. 2 exhibits the Electronic Transmission Microscopy image of thesulfided material prepared in Example 1, characteristic of the catalyticcomposition, object of this invention: a) Electron Microscopy imageshowing the morphology of Group VIB metal sulfur nanospheres with highdensity and Group VIII metal nanospheres, b) high resolution ElectronMicroscopy image showing the hollow nanospheres containing between 2 and10 structural layers.

DETAILED DESCRIPTION OF THE INVENTION

This invention is related to a process for the preparation of acatalytic composition that is composed of at least one Group VIIInon-noble metal and at least one Group VIB metal, and also an organiccomponent as a carbon precursor in close interaction with the metals.The process includes the preparation, mixture, and reaction of thesolutions that contain precursor salts with a solution that contains anorganic component and its later crystallization through the eliminationof the excess solvent. In order to achieve a close interaction betweenthe metals and the organic component, all the components should bedissolved completely before beginning the crystallization process.

It is essential for the catalytic composition preparation process,subject of this invention, that all the components be dissolvedcompletely during the addition of the solution that contains an organiccompound or surface active agent. The process includes the mixture andreaction of the solutions that contain the catalyst component metalswith a solution that contains an organic compound or surface activeagent for the formation of a complex of the metals involved that iscompletely soluble in a polar solvent, the same that is latercrystallized through a solvent crystallization or evaporation process.The term, “completely dissolved,” in this context means that neither asuspension nor a precipitate is formed during the mixture of theprecursor salt solutions that contain the surface active agent, that is,that a transparent solution is obtained.

The catalytic composition, object of this invention, comprises at leastone Group VIII non-noble metal and at least one Group VIB metal. TheGroup VIB metals can be molybdenum, tungsten, chromium, or a mixture ofthem, preferably molybdenum and tungsten, and, more specifically,molybdenum. The Group VIII non-noble metals can be iron, cobalt,ruthenium, nickel, preferably nickel and cobalt. Or it can be acombination of the metals such as nickel-cobalt molybdenum,nickel-cobalt-tungsten, or nickel-cobalt-molybdenum-tungsten, ornickel-cobalt-molybdenum-tungsten-chromium, preferablynickel-cobalt-molybdenum.

The molar ratio of the Group VIB/Group VIII metals applied in theinvention's process varies from 0.1 to 10, preferably from 0.4 to 2, andmore specifically, from 0.5 to 1.5. When the catalytic compositionincludes molybdenum and tungsten as Group VIB metals, the Mo/W molarratio varies from 10 to 1, preferably from 10 to 5. The fact that GroupVIB elements are made up exclusively of molybdenum, for economicreasons, is of special consideration, since the incorporation oftungsten increases the catalyst's density and the cost of said metal ismuch greater than the cost of molybdenum. When the catalytic compositionis made up of nickel and cobalt as in Group VIII metals, the Ni/Co molarratio varies from 0.05 to 20, preferably from 0.1 to 10.

When water is used as the polar solvent, the Group VIB metal component'sprecursor salt can be: molybdenum acetylacetonate, ammonium molybdate,molybdic acid, ammonium tungstate, tungstic acid, preferably ammoniummetatungstate, and/or ammonium heptamolybdate.

If water is used as the polar solvent, the Group VIII metal component'sprecursor salt can be: nitrate, chloride, acetylacetonates, acetate,sulfate, hydroxide, preferably nitrate and/or chloride. When the GroupVIII metal refers to nickel, the precursor salt can be: nickel nitrate,nickel chloride, nickel acetate, nickel citrate, preferably nitrateand/or nickel chloride. When the Group VIII metal refers to cobalt, theprecursor salt can be: cobalt nitrate, cobalt chloride, cobalt acetate,cobalt citrate, preferably nitrate and/or cobalt chloride.

The preparation of the solutions can be carried out separately, that is,each metallic component's precursor salt can be dissolved independentlyin a polar solvent, which can be water or alcohol or a mixture of them,and then mixed to form a solution that contains all the completelydissolved metallic components in a determined concentration for eachcatalytic formulation. Optionally, the solution's preparation can alsobe carried out through the dissolution of the precursor salts in thesame container in order to form a crystalline solution that contains themetallic components involved in a completely soluble state. When ametallic component's non-soluble precursor is used, the conditions forthe total digestion of the insoluble solid through the temperatureincrease and the addition of a base or acid should be sought in orderfor all the metals involved in the catalyst's synthesis to be in acompletely soluble state. On the other hand, the solution that containsan organic compound or surface active agent is prepared separately,through the dissolution of a quaternary ammonium salt or an ionic orneutral surfactant, in a polar solvent such as water, alcohol, or amixture or them.

In the preparation of the solution that contains at least one Group VIBmetal's metallic component, which can be molybdenum, tungsten, and/orchromium, preferably molybdenum and tungsten and more preferably justmolybdenum, this metal's precursor salt, such as ammoniumheptamolybdate, molybdic acid, molybdenum acetylacetonate, molybdenumtrioxide, and/or ammonium metatungstate, tungstic acid, tungstentrioxide, preferably ammonium heptamolybdate or ammonium metatungstate,is dissolved in a polar solvent.

The solution that contains at least one Group VIII non-noble metal, suchas cobalt, nickel, iron, ruthenium, etc., preferably nickel and/orcobalt, is prepared through the dissolution of a precursor salt such asnitrate, chloride, acetylacetonate, acetate, sulfate, hydroxide, ornickel carbonate and/or cobalt, preferably nitrate, chloride, oracetate, in a polar solvent that may be water, alcohol, or a mixture ofthem.

The solution that contains the organic compound as a carbon sourceprecursor is prepared through the dissolution of a quaternary ammoniumsalt or a solid surface active agent in a polar solvent. The surfaceactive agent such as a cationic, anionic, or neutral surfactant,preferably cationic or neutral, is for achieving an optimal interactionbetween the anions formed by the inorganic components. The surfaceactive agent may be a salt of a tetraalkyl ammonium ion (NR₄ ⁺) where Ris the alkyl group and corresponds to a saturated hydrocarbon chain oralkyl groups that can contain from 1 up to 8 carbon atoms each. All thealkyl groups can contain the same carbon number or can each be differentsizes. The tetraalkyl ammonium ion may be halogenated, substituted withchlorine or bromine; or, may be hydroxylated, that is, substituted withhydroxyl groups (OH). The surface active agent may be a cationicsurfactant with a larger alkyl group chain, represented by R′NR₃, whereR′ corresponds to a long chain of saturated hydrocarbons or an alkylgroup containing between 12 and 20 carbons and R is the other alkylgroup and corresponds to a short chain of hydrocarbons that containsbetween 1 and 8 carbon atoms.

The solutions that contain the metallic components and the organiccompound are mixed with continuous stirring; then, a concentrated basesolution is added, such as ammonium hydroxide, ammonium carbonate,and/or sodium hydroxide or potassium, preferably ammonium hydroxide,until the solution's pH rises to a value comprised between 5 and 14,preferably between 8 and 12. Then, the solution's temperature isincreased to a value comprising between 50 and 200° C., preferablybetween 60 and 100° C., while the basic solution is added in order tomaintain all the components in a completely dissolved state and it iskept in stirring for a period of time comprised between 5 min. and 24 h,preferably from 5 min to 10 h, in order to achieve a perfect interactionbetween all the metallic components involved and the organic compoundcarbon precursor. Having all the metallic species involved in acompletely dissolved state in a polar solvent in the presence of anorganic compound allows the maximum interaction between them and theyreact forming a mixed complex between the inorganic and organiccomponents when the crystallization of the aforementioned takes place.

In the event that the polar solvent used is water, it is preferable thatthe reaction temperature be less than its boiling temperature, that is,between 60 and 100° C., and that the reaction take place in an opencontainer at atmospheric pressure, or with a solvent reflux system. Inthe event that a higher temperature than the boiling point of water isused, the reaction should be carried out in a closed container underautogenous pressure such as an autoclave, where the crystallization ofthe components present in the prepared solution should be carried outunder hydrothermal conditions and autogenous pressure.

It's important for the preparation process that is the object of thisinvention to adequately select the reaction temperature and pH in orderto maintain all the metallic components involved in the preparation ofthe catalyst in a completely soluble state; the pH interval is from 5 to14, preferably between 8 and 12, and more preferably between 8 and 10.The reaction time varies between 5 minutes and 24 h, preferably between5 min and 10 h, and more preferably between 5 min and 5 h.

Once the time necessary has passed for an optimal interaction andreaction between all the components involved, the completely crystallinesolution or solution in a completely soluble state passes to acrystallization process that consists of the elimination of the excessammonium ions and the evaporation of the polar solvent, preferablywater. As the excess solvent is eliminated, a precipitate is formed thatmay be green or purple in color depending on whether the nickel or thecobalt content is predominant. The yield of the material obtaineddepends on the solvent's degree of evaporation, and it is possible toobtain a yield greater than 99% if the crystallization process isadequately controlled.

The crystallization process of the solution that contains all the metalsinvolved in the catalyst's preparation may be instantaneous or gradualand may take place in a continuous manner or in batches. For thisreason, the process is viable for large scale implementation, such as ina batch reactor and/or in an evaporator.

When the crystallization is carried out through gradual evaporation, asubsequent solid-liquid separation process is required in order torecover the precipitate, which can be via filtration and/orcentrifugation. Small quantities of metals remain dissolved in themother liquor, in order to avoid losing this quantity of metalscontained in the mother liquor resulting from the separation; thisshould recycle the process that is the object of the present invention.Once the solid material is obtained, whether it be dry or wet, it issubjected to a drying process that can be static, in a stove, or througha hot air flow or through continuous drying process in a dryer orequivalent, at a temperature comprised between 50 and 300° C.,preferably between 80 and 150° C.

This invention also considers the addition of an inorganic oxide, or amixed oxide, as a binding agent in order to produce catalysts with ageometric form, selected from a group of existing binders such asalumina, titania, alumina-titania, zeolites, silica, and silica-alumina,all of them stable supports for hydrotreatment catalysts. The term,“binder or binding agent,” refers to an inorganic oxide that is capableof integrating or binding the material's particles in the form ofextrudes, pellets, or spheres, in order to put them in adequate form fortheir use in a fixed bed catalytic process.

The addition of the binding agent can be carried out in different stagesof the catalyst preparation process that is the object of thisinvention. If desired, it can be added in the form of the inorganicoxide's precursor salt during the dissolution of the Group VIII andGroup VIB metallic elements' precursor salts. The inorganic oxide'sprecursor salts selected as binders are nitrates, chlorides, acetates,sulfates, hydroxides, etc. Said precursor salt will precipitate as soonas the basic solution, composed of a hydroxide and/or ammonium carbonateand/or sodium, is added. On the other hand, the addition of the bindercan also be carried out once the reaction stage has been completedthrough the incorporation of the binding agent in powder form into thesolution that contains the metallic and the organic component complex;and, afterward, the crystallization is carried out through theevaporation of the solvent in the presence of the binding agent.Preferably, the addition of the binder to the catalyst's drycrystallized particles that contain the metallic components selectedfrom Group VIII and Group VIB can be carried out. Specifically, thebinder may be dry or in a wet state peptized with an inorganic ororganic acid such as nitric acid, hydrochloric acid, phosphoric acid,boric acid, sulfuric acid, citric acid, acetic acid, etc, preferably,phosphoric acid, citric acid, nitric acid, and/or acetic acid. In theevent that the mixture of both parts is carried out, that is, the binderand the catalyst's particles in dry state, the binder's peptization iscarried out through the addition of a diluted organic or inorganic acid.Afterward, the homogenous mixing of the wet binder particles and thecatalyst is carried out in a Muller kneader until a perfectly homogenousand uniform paste is obtained with the adequate rheological propertiesto be extruded.

The material used as a binder or binding agent may be selected amongstthe materials conventionally used as binders in the hydrotreatmentcatalysts. In addition, a group of oxides, hydroxides, oxy-hydroxides,etc., such as silica, silica-alumina, aluminas such as boehmite,pseudoboehmite, bayerite, gibbsite, and/or aluminum oxides such asgamma, eta, theta, and chi aluminas, zirconia, zirconia-alumina,zirconia-silica, zeolites with different structures: ZSM-5, Beta, Y, X,etc. may be selected. The silicoaluminates from the family of MCMmaterials can also be selected. Titania with different structures suchas anatase, rutile, and brokite, mixed titanates from hydrogen and/orsodium with nanotubular and/or nanofibrillar morphology of high specificarea, titania-alumina, titania-zirconia, titania-silica, etc. may alsobe selected. Preferably, the binders are alumina, zirconia, silica,silica-alumina and titania, and/or mixtures of these components. Morepreferably, they are alumina, zirconia, titania, alumina-titania, andzirconia-titania. The employment of titania such as titaniumoxy-hydroxides, hydrogen titanates, and/or mixed titanates from hydrogenand/or sodium with nanofiber and/or nanoplate morphology of highspecific area and low density is the special preference of thisinvention; and/or the employment of alumina binders, equally withnanofibrillar and/or nanoplate morphology of high area and low density.The selected binder's surface area generally varies between 20 and 700m²/g, preferably between 150 and 500 m²/g, measured by nitrogenphysisorption and applying the BET Method, and has pore volumes thatvary from 0.05 up to 2.5 cm³/g, preferably between 0.1 and 2 cm³/g.

The binder's composition in the catalyst's final composition variesbetween 0 and 50 wt. % of the total of the catalyst's components in itsoxidized form, preferably between 0 and 40 wt. %, and more preferablybetween 0 and 20 wt. %. Although, the binder's composition should beadjusted in function of the application in question, of the activity,and of the mechanical resistance that are desired in the final catalyticcomposition. The catalyst formulation process that is the object of thisinvention includes the formulation of extrudes, pellets, spheres, and/ormicrospheres, preferably the formulation of extrudes and/or pellets, inorder to be applied in a fixed bed process. The extrudes formulated maybe cylindrical of radial sizes comprised between 1/20 to ⅛ of an inch,or may be trilobular or tetralobular.

The extrusion process is carried out in a mechanical extruder coupledwith dies with orifices of different diameters in order to prepareextrudes of different sizes, as was already indicated. Once the extrudesare obtained, these are put at rest for a period of time comprisedbetween 5 min and 12 h, preferably between 5 min and 5 h. Afterward,they are subjected to a drying process on a stove in static airatmosphere, or through a warm air flow, at a temperature comprisedbetween 50 and 300° C., preferably between 80 and 150° C., or in acontinuous dryer with controlled atmosphere at a temperature comprisedbetween 50 and 300° C. In this stage, the catalysts are formulated asextrudes, pellets, or spheres that may or may not be calcined in orderto have them in their oxidized form. The catalyst contains an organiccompound added as a surface active agent, which leaves a carbon residueupon being thermally treated, which is why it is desirable to apply athermal treatment in order to stabilize the extrudes and give themgreater mechanical strength. Under no circumstance should this becarried out in oxygen or air atmosphere. The thermal treatment should becarried out in inert atmosphere, which can be in a flow of nitrogen,argon, helium, or a mixture of them. This thermal treatment should becarried out at a temperature comprised between 200 and 1000° C.,preferably between 300 and 600° C., and more preferably between 300 and500° C., for a time comprised between 0.1 and 24 h, preferably between0.5 and 10 h. The inert gas flow that passes through the catalyticcomposition catalyst during the thermal treatment is comprised between0.01 and 5 L/g·min, preferably between 0.01 and 1 L/g·min. The dryextrudes may not be subjected to a thermal treatment and pass directlyto a sulfiding stage, also an object of this invention.

The catalytic composition's preparation process, object of thisinvention, includes a sulfiding stage. This stage consists of puttingthe catalyst's particles in contact, whether it be before or after thethermal treatment in inert atmosphere, with a liquid or gaseous streamthat contains sulfur compounds and a gaseous stream of hydrogen. Thesulfur compounds used for the sulfiding may be hydrogen sulfide,dimethyl disulfide, carbon disulfide, thiophenes, polysulfides,benzothiophenes, or a stream of hydrocarbons that contains sulfuringorganic compounds. Optionally, the sulfiding can be carried out on acatalytic composition containing dry carbon or carbon thermally treatedin inert atmosphere. The sulfiding procedure in gaseous phase consistsof making a flow of between 0.5 and 30 vol. % of H₂S, balanced withhydrogen over a fixed bed of the catalytic composition at a temperaturecomprised between 200 and 600° C., preferably between 250 and 500° C.,in order to obtain the material in its sulfided state. The sulfidingprocedure in liquid phase consists of putting the catalytic compositionin contact with a liquid stream of hydrocarbons that contains between0.1 and 5 wt. % of sulfur, such as sulfur organic compounds, orcompounds enriched with DMDS, thiophenes, or CS₂, with a hydrogen flowat a temperature comprised between 200 and 600° C., preferably between250 and 500° C., at a pressure comprised between 1 and 100 Kg/cm².

For its application in hydrocarbon hydrotreatment reactions in a fixedbed reactor, the sulfiding should be carried out “in situ” before orafter the thermal treatment. Preferably, the sulfiding should be carriedout “in situ” and directly over the dry catalytic composition thatincludes an organic component containing carbon and/or after havingstabilized it through a thermal treatment in inert atmosphere. After thethermal treatment in inert atmosphere, the catalytic composition, objectof this invention, is composed of at least one Group VIII non-noblemetal and at least one Group VIB non-noble metal in its oxidized stateand contains, in addition, carbon. If the Group VIB metal component ismolybdenum, as is the preference of this invention, the x-raydiffraction pattern presented the characteristic peaks of a nickeland/or cobalt molybdate structure with beta and/or alfa structure or amixture of the two phases, such as is observed in FIG. 1. If thecatalytic composition is composed of tungsten and/or molybdenum, or in ahigh concentration of tungsten, the x-ray diffraction pattern presentedwide peaks characteristic of an amorphous material, and that can not beassigned to any phase already reported in the Joint Committee on PowderDiffraction Standards (JCPDS) cards.

If the Group VIII non-noble element is nickel, and the Group VIB elementis molybdenum, the x-ray diffraction shows the peaks characteristic ofthe nickel molybdate, in its alpha- and/or beta-phase, or it may be thatthe x-ray diffraction peaks correspond to both phases. In the alphaphase, the structure is monoclinic where the molybdenum istetracoordinated in a tetrahedral symmetry, and the nickel ishexacoordinated with octahedral symmetry, while the beta-phase presentsan orthorhombic structure where the molybdenum and nickel arehexacoordinated with octahedral symmetry. If the Group VIII non-noblemetallic component's element is cobalt and the Group VIB metallicelement is molybdenum, the x-ray diffraction peaks correspond to thecobalt molybdate in its alpha and/or beta phase, or a mixture of the twophases. When the Group VIII non-noble components consist of a mixture ofnickel and cobalt, then the x-ray diffraction peaks correspond to amixed molybdate of nickel-cobalt in alpha and/or beta phase, or amixture of them.

After the thermal treatment in inert atmosphere, the catalysts thatcontain carbon, at least one Group VIII non-noble metal, and at leastone Group VIB metal, presented specific areas comprised between 50 and300 m²/g, preferably between 70 and 150 m²/g, pore volumes between 0.05and 1.5 cm³/g, preferably between 0.1 and 0.7 cm³/g. The pore diametersof the catalysts after thermal treatment in inert atmosphere arecomprised between 3 and 20 nm, preferably between 3 and 10 nm,determined by nitrogen physisorption.

The textural properties of the catalysts depend to a great extent on thequantity of binder or binding agent used for the formulation of theextrude in the event that said extrude is used in the catalyticcomposition. And in turn, the quantity of binder added depends on theactivity that is desired in the catalytic composition and varies between0 and 50% in total weight of the catalyst's components in its oxidizedform, preferably between 0 and 40 wt. %, and more preferably between 0and 20 wt. %. Although, the binder's composition should be adjusted infunction of the application in question, as well as of the activity, andof the mechanical resistance that are desired in the final catalyticcomposition.

It is important that the catalyst's particles be uniformly and closelydistributed in the binder, which acts as a binding gum for thecatalyst's particles and allows them to be formulated as extrudes,pellets, and/or spheres, in such a manner that they can be evaluated ina continuous fixed bed hydrotreatment process. In this way, with thebinder compositions described previously, the catalysts present amechanical side crushing strength of at least 2 lb/mm, preferably 4lb/mm, or greater.

In its sulfided form, the catalytic composition that is the object ofthis invention consists of sulfides of at least one Group VIII non-noblemetal and one VIB metal and, in addition, residual carbon coming fromthe organic compound added during the crystallization stage. When abinder is added, in addition to the sulfides and carbon, it alsoconsists of an inorganic oxide selected from a group of materials, or ofconventional supports for hydrotreatment catalysts.

After the thermal treatment and subsequent sulfiding, or after thedirect sulfiding, the catalytic composition contains carbon at aconcentration comprised between 0 and 10 wt. %, preferably between 0.05and 5 wt. %, based on the total composition of oxides and/or of sulfurs.The carbon may be present forming a kind of sulfide carbide in very lowconcentration, or in the form of amorphous carbon.

After a sulfiding treatment, at least 60% of the oxidized phases of atleast one Group VIII non-noble metal and of at least one Group VIB metalhave been sulfided, preferably at least 80% of the metals have beensulfided, and more preferably at least 95% of the metals involved in thecatalytic composition have been sulfided. The presence of an organic orcarbon component favors the sulfiding of the metals involved in thecatalytic composition.

The catalytic composition's x-ray diffraction patterns in its sulfidedphase presented crystalline peaks that can be attributed to crystallinephases from Group VIII non-noble metal sulfides and to Group VIB metalsulfides and to Group VIII and Group VIB mixed metal sulfides, as can beobserved in FIG. 1 (c).

It was determined through Electron Transmission Microscopy that thecatalytic composition that is the object of this invention is made up ofparticles with a laminar structure with a great density of them curvedforming fullerene nanoparticles with a stacking level between thelaminae of 2 to 20 layers, as can be appreciated in FIG. 2 (a, b).

Whether it be because of direct sulfhydration of the catalyticcomposition or because of sulfiding of the oxidized species through aprevious thermal treatment of the catalytic composition containing atleast one Group VIII non-noble metal and at least one Group VIB metal,and residual carbon, the active sulfided species were evaluated as acatalyst in the hydrocarbon hydroprocessing reaction, preferablyhydrodesulfuration and hydrodenitrogenation and hydrodearomatization oflight and intermediate petroleum fractions.

In the specific case of this invention, light and intermediate petroleumfractions are considered to be those that include hydrocarbons whoseboiling points are equal to or less than 180° C., and intermediatepetroleum fractions are considered to be those that include hydrocarbonswhose boiling points are equal to or greater than 180.1° C. and lessthan or equal to 400° C.

In the case of the hydrodesulfurization reactions, which is one ofapplications of this invention's catalytic composition, adibenzothiophene (DBT) molecule model was used, without this limitingits application, since said compound represents a molecule model forhydrodesulfuration reactions of light and intermediate petroleumfractions (M. Daage and R. R. Chianelli, J. Catal. 149, 414-427 (1994)).With the goal of minimizing the exposure of the sulfided catalysts tothe environment and avoiding their deactivation due to the formation ofsulfated species, the sulfided material is put in contact with thehydrocarbon that contains the DBT model molecule in a glove chamber andthen is loaded into an autoclave reactor. Preferably, the catalystshould be added under inert nitrogen, helium, or argon atmosphere inorder to avoid its sulfation to the extent possible.

The control of the quantity of DBT in the reaction mixture to behydrodesulfurated is carried out in a manner similar to the previousprocedure. That is, a quantity of hydrocarbon is weighed on a highprecision analytic scale, then the quantity of DBT that one wishes tohydrotreat is added, and then the catalyst is added, thus avoiding itsexposure to the environment, in a glove chamber and in inert atmosphere.

When one wishes to hydrodesulfurize a light or intermediate petroleumfraction, the addition of the catalyst is carried out directly over 10ml of the desired fraction, which is completed at 100 ml with an organicsolvent before beginning the hydrodesulfuration reaction.

The hydrodesulfuration reaction was carried out in a three-phase reactorby autoclave batches in which the reaction mixture is added, whether itbe formed by hydrocarbon used as solvent and DBT or the petroleumfraction that one wishes to hydrodesulfurate, containing the catalystthat one wishes to evaluate.

Once the reactor has been loaded, the system is pressurized with aninert gas, such as nitrogen, helium, and/or argon, preferably nitrogen,with the aim of purging the air present. Afterward, the mechanicalstirring was begun between 100 and 2000 rpm, preferably between 800 and1500 rpm, with the goal of eliminating the presence of internaldiffusion effects. Afterward, the reactor's temperature was elevated tothe final operating temperature in the interval of 300 to 400° C.,preferably between 320 and 360° C. Finally, the operating pressure wasadjusted through the addition of hydrogen between 40 and 100 kg/cm²,preferably between 50 and 70 kg/cm².

Once the reaction conditions described in the previous paragraph werereached, the catalytic evaluation through frequent samplings was carriedout with the purpose of determining parameters such as the conversion,reaction speed, selectivity, and yield. For this reason it wasconsidered a pseudo-first order reaction model with respect to thereacting hydrocarbon, and zero order with respect to the hydrogen due tothe fact that it was fed a great excess of the latter. For theidentification and quantification of the products resulting from thereaction, the liquid samples taken were analyzed in a chromatograph withVarian 3400 CX gases equipped with a flame ionization detector and anUltra 2 Capillary Column (Crosslinked 5% Ph Me Silicone). When a realload is used, the total concentration of sulfur was determined in an HPsievers gas chromatograph, equipped with a chemiluminescence detector(SCD) and a capillary column. The catalytic activity was determinedthrough the calculation of the specific velocity constant of reaction(K) on the formulations of catalysts that are the object of thisinvention, which is defined in [L/g·s].

For comparison purposes, the catalytic activity of a commercial catalystwas determined, based on the same active components deposited on a highspecific area support with an alumina base, on which the reaction'sspecific velocity constant was determined. This determination was usedas the reaction's velocity constant of a reference catalyst, and wasnamed as the reference constant that served to determine the relativeactivity of the catalysts that are the object of this invention, definedas the ratio between the catalyst's activity and the referencecatalyst's activity. Said ratio is the reaction velocity constant of acatalyst divided between the reaction's reference constant over acommercial reference catalyst.

In the cases in which the reaction was carried out with DBT as thehydrodesulfuration reaction model molecule, the catalytic formulations,objects of this invention, presented selectivity comprised between 30and 40% toward the formation of biphenyl (BP) between three and fourhours of reaction, and a selectivity between 60 and 70% towardciclohexyl phenyl (CHP) and biciclohexyl (BCH) as hydrogenation productsof the aromatic rings that make up the BP, which indicates that thesecatalysts possess a high hydrogenating capacity. Said hydrogenatingcapacity was determined through the ratio of reaction productselectivities dividing the CHP selectivity plus the BCH selectivity bythe BP selectivity [(S_(CHP)+S_(BCH))/S_(BP)]; the hydrogenatingcapacity of the catalysts that are the object of this invention turnedout to be superior to that of the conventional catalysts based on thesame metals supported on alumina. It was demonstrated that the presenceof carbon in the catalytic composition favors not only thehydrodesulfuration's rate, but also the material's hydrogenatingcapacity. When a binder is added to the catalytic composition containingcarbon, object of this invention, the hydrodesulfurating capacitydeclines slightly; however, its hydrogenating capacity diminishesdrastically. The ratio of selectivities [(S_(CHP)+S_(BCH))/S_(BP)]comprised between 1 and 3, preferably between 1.5 and 2.5, diminishes toa value comprised between 0.05 and 0.5. Generally, in the commercialcatalysts based on the same metals this ratio is comprised between 0.1and 0.3.

Additionally, the presence of carbon in the catalytic composition of atleast one Group VIII non-noble metal and at least one Group VIB metal,containing a binder or binding agent, favors its desulfuration capacityand promotes its hydrogenating capacity. Therefore, the presence ofcarbon in the catalytic composition that is the object of this inventionturns out to be of vital importance in order to access high performancecatalysts that achieve deep hydrodesulfuration levels and fuels of verylow sulfur content.

Finally, in Example 12 the hydroprocessing capacity of this invention'scatalytic composition is demonstrated for a primary light gas oil (PLGO)with a high nitrogen content, between 250 and 500 ppm, whose propertiesare shown in Table 3. The catalytic composition that is the object ofthis invention presented a catalytic activity approximately 5 timesgreater than the catalytic activity of a conventional commercialcatalyst with the same metallic components supported on alumina, asindicated in Table 4. The sulfur content of the product obtaineddiminished to levels inferior to 30 ppm in sulfur weight, when theevaluation was carried out at a spatial velocity of 2.5 h⁻¹, while whenthe spatial velocity diminished to 1.5 h⁻¹ the sulfur content in thefraction of the product diminished to levels inferior to those of 10 ppmin weight. Therefore, the application of the catalytic composition thatis the object of this invention in the hydrodesulfuration of light andintermediate fractions represents an alternative for achieving ultra-lowsulfur fuels.

EXAMPLES Example 1

11.93 g of ammonium heptamolybdate [(NH₄)₆Mo₇O₂₄], 21.18 g of nickelnitrate [Ni(NO₃)₂.6H₂O], and 0.33 g of cetyl trimethyl ammonium bromide(CTAB) are dissolved in 150 ml of deionized water. A green-coloredcrystalline solution is obtained with a pH between 4 and 6; afterward, a28 vol. % ammonium hydroxide solution is added, approximately 125 ml,until reaching a pH between 8 and 10; the solution remains crystallineand its coloration changes from green to blue. Then, the solution isheated to a temperature of 79-90° C., allowing the evaporation of theexcess water (125 ml) and the formation of a green precipitate. Thesuspension formed presents a pH of 7.3. The material obtained isfiltered, washed with an abundant amount of deionized water, and driedat 120° C. for a period of 18 hours.

The material obtained in powder form presented a crystalline structurecharacteristic of a mixed ammonium oxy-hydroxide of molybdenum andnickel whose formula is expressed as follows: (NH₄)HNi₂(OH)₂(MoO₄)₂, seeFIG. 1( a). Then, 5 g of the material made up of the ammoniumoxy-hydroxide of molybdenum and nickel containing the organic compoundwere sulfided directly at 400° C., in a quartz tube making a flow of 100ml/min From a mixture of gases made up of 10 vol. % of H₂S and 90 vol. %of H₂ for 2 hours. Afterward, the solid was allowed to cool at roomtemperature. In its sulfided phase, the material presented a mixture ofcrystalline phases made up of Ni_(2.5)Mo₆S_(6.7) and NiS_(1.19) (seeFIG. 1( c)). The mixed sulfide of molybdenum and nickel obtainedpresented a fullerene morphology, that is, it is made up of nanosphereswith dimensions comprised between 5 and 20 nm, with a stacking levelbetween the layers comprised between 2 and 10 structural layers.

One part of the sulfided material in powder form (80:100 Tyler mesh) wasevaluated in the dibenzothiophene (DBT) hydrodesulfurization reaction,avoiding its exposure to the environment to the maximum extent possible.100 ml of a solution prepared with 0.3 g of DBT dissolved in 100 ml ofn-hexadecane were placed in a 500 ml autoclave to which 0.2 g of thesulfided material was added as a catalyst. The reactor was sealed andpurged with inert gas. Afterward, the temperature was increased to 320°C. at a heating rate comprised between 2 and 20° C./min and the hydrogenpressure was adjusted to 56 Kg/cm². It was allowed to react for a periodcomprised between 4 and 6 hours, taking an aliquot from the reactionmixture every 30 minutes for its analysis by gas chromatography. InTable 1 it is observed that at the end of 4 hours of reaction the DBTconversion turned out to be 96% and its reaction rate constant was1.48*10⁻⁴ l/g·s.

The selectivity toward biphenyl (BP) turned out to be 32.75 mol %, whilethe selectivity toward products like cyclohexyl phenyl (CHP) andbicyclohexyl (BCH) turned out to be greater than 67.25%. This highselectivity toward CHP and BCH indicates that this catalyst possesses ahigh hydrogenating capacity. The hydrogenating capacity of this catalystwas determined through the ratio of selectivities from the reactionproducts dividing the CHP selectivity plus the BCH selectivity betweenthe selectivity of BP [(S_(CHP)+S_(BCH))/S_(BP)]; said ratio turned outto be greater than 2.05, which indicates a high hydrogenating power.

Another fraction of the sulfided material was evaluated as a catalyst inthe hydrodesulfuration of a primary light gas oil (PLGO) in anautoclave. For this experiment, 20 ml of PLGO with the characteristicsreported in Table 1 were diluted in 80 ml of hexadecane; this mixturewas placed in a 500 ml autoclave reactor, adding 2 g of the sulfidedmaterial as a catalyst, strained to a particle size comprised between80-100 Tyler mesh. The reactor was sealed, purged with nitrogen, andthen the temperature was increased to 350° C. at a heating ratecomprised between 2 and 20° C./min. Once the temperature was reached,the hydrogen pressure was adjusted to 70 Kg/cm² and it was allowed toreact for 6 hours. The initial concentration of sulfur in the reactionmixture was around 2688 ppm, and after the 6 hours of reaction, thereaction's liquid product contained 35 ppm of sulfur. The reaction rateconstant determined for this evaluation was 3.42*10⁻⁶ L/g·s.

Example 2

In order to evaluate the influence of the surface active agent added asa residual carbon precursor in the catalytic composition, the materialprepared in Example 1 was calcined at a temperature of 400° C., in airatmosphere. The oxidized phase of the material obtained presented acrystalline structure corresponding to the β-NiMoO₄ phase, and a smallquantity of α-NiMoO₄ phase (see FIG. 1( b)) whose morphology consists innanoparticles of the nickel molybdenum mixed oxide and presented a BETsurface area of 105 m²/g, an average pore volume of 0.18 cm³/g, and anaverage pore diameter of 6.9 nm.

The material in its oxidized form is subjected to a sulfiding treatment.In order to do this, it is heated at a rate of 4° C./min until reaching400° C., in a quartz tube using a nitrogen flow of 100 ml/min. Oncereaching 400° C., the nitrogen flow is changed for a mixture of gasescomposed of 10 vol. % of H₂S and 90 vol. % of H₂ and is maintained for 2hours.

A portion of the sulfided material in powder form (80:100 Tyler mesh)was evaluated in the hydrodesulfuration reaction of dibenzothiophene(DBT), avoiding its exposure to the environment to the maximum extentpossible. 100 ml of a solution prepared with 0.3 g of DBT dissolved in100 ml of hexadecane were placed in a 500 ml autoclave, to which 0.2 gof the sulfided material were added as a catalyst. The reactor wassealed and purged with inert gas. Afterward, the temperature wasincreased to 350° C. at a heating rate comprised between 2 and 20°C./min and the hydrogen pressure was adjusted to 56 Kg/cm². It wasallowed to react for a period comprised between 4 and 6 hours, taking analiquot from the reaction mixture every 30 minutes for its analysis bygas chromatography. As can be observed in Table 1, at the end of 4 hoursof reaction, the DBT conversion turned out to be 87% and its reactionvelocity constant was 9.34*10⁻⁵ L/g·s. These results were significantlyless than those reported in Example 1, where there was no calcination oroxidation treatment, and the organic compound included in Example 1,formed residual carbon in the inert atmosphere heat-treatment procedure.

The selectivity toward biphenyl (BP) turned out to be 35.52% mol, whilethe selectivity toward products like cyclohexyl phenyl (CHP) andbicyclohexyl (BCH) turned out greater than 64.48 mol %. This highselectivity toward CHP and BCH indicates that this catalyst possesses ahigh hydrogenating capacity of 1.82, determined in the same manner as inExample 1; however, this value was lower than the value observed inExample 1, where the catalytic composition contains residual carbon.

It can be deduced from the comparison of Examples 1 and 2 that theaddition of a surface active agent as a residual carbon precursor in thecatalyst favors and promotes the desulfuration rate and thehydrogenating capacity of the catalysts.

Example 3

This example follows the same methodology described in Example 1. Inthis example, a material was prepared without the addition of a carbonprecursor organic component. The quantities of the salts used for thisexample where the same as in Example 1, without addition of CTAB as asurface active agent. The resulting precipitate is filtered and washedwith an abundant amount of deionized water.

The dry material obtained presented the same crystalline structure as inExample 1, corresponding to an ammonia complex of nickel-molybdenumoxy-hydroxide, such as is presented in FIG. 1.

The material was sulfided directly with the procedure described inExample 1. The material in powder form was evaluated as a catalyst,following the procedures described in Example 1 in thehydrodesulfuration reaction of DBT, obtaining a conversion of 96 mol %during the 6 hours of reaction with a reaction rate constant of1.02*10⁻⁴ L/g·s. Therefore, this catalyst turned out to have an activitythat was 50% less than that obtained in Example 1 with a composition inwhich a residual carbon precursor surface active agent was added, andvery similar catalytic activity with regards to Example 2 where thecarbon has been eliminated through calcination at 400° C. in airatmosphere. The importance of the addition of the surface active agentas a residual carbon precursor during the catalyst's preparation isdeduced from this comparison.

The evaluation with PLGO was carried out under the same conditions as inExample 1. After 6 h of reaction, a final product was obtained with asulfur content lower than 48 ppm in weight and the reaction rateconstant was 2.85*10⁻⁶ l/g·s, lower than that observed in the same testin Example 1.

Example 4

The dry material obtained in Example 3 was calcined in air atmospherefollowing the same procedure described in Example 2. In its oxidizedphase, the material presented the same crystalline structures reportedin Example 2; however, the BET surface area was 92 m²/g, the pore volumewas 0.132 cm³/g, and the average pore diameter was 5.1 nm. The materialin its oxidized form is subjected to a sulfiding treatment. To do this,it is heated at a rate of 4° C./min, until reaching 400° C., in a quartztube with a nitrogen flow of 100 ml/min. Once the 400° C. are reached,the nitrogen flow is changed for a mixture of gases composed of 10 vol.% of H₂S and 90 vol. % of H₂ and is maintained for 2 hours. One part ofthe sulfided material in powder form (80:100 Tyler mesh) was evaluatedin the hydrodesulfuration reaction of dibenzothiophene (DBT), avoidingits exposure to the environment to the maximum extent possible, throughthe procedure and the conditions described in Example 1.

As can be observed in Table 1, at the end of 4 hours of reaction the DBTconversion turned out to be 89% and its reaction rate constant was7.5*10⁻⁵ L/g·s. These results were significantly lower than thosereported in Examples 1 and 3, where there was no calcination treatment,and significantly inferior to that of Example 2 with similar calcinationtreatment where the organic compound added during the mixing andreaction stage in the synthesis has been eliminated. However, thedistribution of product selectivities was practically identical to thatobtained in Example 3, as can be appreciated in Table 1. That is to say,both catalysts presented the same hydrogenating capacity due to the factthat in this case there was no organic compound precursor to eliminateduring the calcination.

Example 5

In this example, a catalyst was prepared through the precipitation ofthe nickel molybdenum mixed oxy-hydroxide in the presence of a binder orbinding agent. An alumina in its boehmite phase was used with a surfacearea of 243 m²/g, an average pore volume of 0.336 cm³/g, and an averagepore diameter of 5.54 nm. For this, just as in Example 1, 11.93 g ofnickel nitrate, 21.18 g of ammonium heptamolybdate, and 0.33 g of asurface active agent (CTAB) were dissolved in 150 ml of water (pH=5).The solution acquired a green color, then this solution was heated to90° C. and 125 ml of ammonium hydroxide (pH=10) were added; thecrystalline solution acquired a blue coloration. This solution wasmaintained for a period of 30 minutes heating to 90° C.; afterward,68.25 g of boehmite (Catapal) were added. In order to remove the waterby evaporation, the solution with the added boehmite continued heatingfor approximately three hours at the temperature indicated earlier untila change in color from blue to green, and then to a light green, wasnoticed. The precipitate obtained was left to cool at room temperatureand was washed with distilled water 4 times, 600 ml each wash. Finally,the product obtained was dried at a temperature of 120° C. for 18 hours.

Afterward, the material was calcined in accordance with the proceduredescribed in Example 1. In its oxidized phase, the material exhibits adiffraction pattern characteristic of the gama-alumina. The catalyst inits oxidized phase contains 16.4% weight of MoO₃, 7.17% weight of NiO,and 76.4% weight of Al₂O₃. This material exhibits a specific areameasured by nitrogen physisorption of 271 m²/g, pore volume of 0.31cm³/g, and a pore diameter of 4.5 nm.

A portion of the dry material is sulfided directly in accordance withthe procedure described in Example 1 in order not to eliminate thecarbon precursor organic compound. Its catalytic activity was evaluatedin the DBT hydrodesulfuration reaction in accordance with themethodology described in Example 1. At the end of 4 h of reaction, itpresented a conversion of 98% and a catalytic activity towardhydrodesulfuration of 1.27*10⁻⁴ L/g·s.

The selectivity toward BP turned out to be 79.07% mol while theselectivity toward the hydrogenated products CHP and BCH turned out tobe 20.93% mol. The hydrogenating capacity was determined as in Example1, through the ratio of selectivities [(S_(CHP)+S_(BCH))/S_(BP)], was0.26, much less that that observed in Example 1. Although thehydrodesulfuration rate was high, its hydrogenating capacity turned outto be low, compared with Examples 1 through 4, where the catalyticcomposition does not contain a binder.

Example 6

Example 6 was carried out in accordance with the methodology describedin Example 5. In this case, the surface active agent was not addedduring the preparation of the ammonium heptamolybdate salts and nickelnitrate solution. The crystallization was carried out in the presence ofa binder, the same one used in Example 5.

A portion of the material was calcined in air atmosphere in order toobtain the material in its oxidized phase. This material's x-raydiffraction pattern mainly exhibits the peaks characteristic of thegama-alumina. In its oxidized phase, the material contains approximately16.4% weight of MoO₃, 7.2% weight of NiO, and 76.4% weight of Al₂O₃. Thespecific area determined by nitrogen physisorption turned out to be 260m²/g, with an average pore volume of 0.29 cm³/g, and a pore diameter of4.5 nm. In comparison with Example 5, this material presented greaterspecific surface when it was prepared in the presence of a surfactant orsurface active agent.

A portion of the material was sulfided directly in accordance with theprocedure described in Example 1. Its catalytic activity was evaluatedin the DBT hydrodesulfuration reaction in accordance with themethodology described in Example 1. After 4 h of reaction, this materialpresented a conversion of 97% and a DBT hydrodesulfuration rate constantof 1.06*10⁻⁴ L/g·s. The selectivity toward BP was 89.04% and theselectivity toward hydrogenation products, CHP and BCH, turned out to10.96%. The catalytic activity of this material turned out to beinferior to the equivalent that contains residual carbon from Example 5.Also, its hydrogenating capacity diminished to 0.12, since it presentsless selectivity toward hydrogenation products like CHP and BCH. Thecomparison of Examples 5 and 6 provides more evidence that theincorporation of an organic compound, such as a surfactant or surfaceactive agent into the synthesis favors the hydrodesulfuration rate andpromotes the hydrogenating capacity of the materials, even when theseare incorporated into a binder.

Example 7

This example corresponds to the evaluation of the catalytic activity ofa commercial catalyst, based on the same metals as the catalyticcomposition that is the object of this invention, supported on aconventional alumina for hydrodesulfuration catalysts. The evaluation ofthe catalytic activity was carried out in the DBT hydrodesulfurationreaction following the procedure described in Example 1.

After 4 h of reaction, the DBT conversion was 96%, and presented areaction rate constant of 1.12*10⁻⁴ L/g·s. The selectivity towardhydrogenation products, basically toward CHP, was 9.53% while 90.47%corresponded to the selectivity toward BP. Its hydrogenating capacity,measured as the selectivity ratio [(S_(CHP)+S_(BCH))/S_(BP)], was barely0.1.

Example 8

Following the methodology described in Example 1, a material wasprepared substituting the nickel salt for a cobalt salt. In order to dothis, 11.93 g of ammonium heptamolybdate, 21.18 g of cobalt nitrate[Co(NO₃)₂.6H₂O], and 0.33 g of cetyl trimethyl ammonium bromide (CTAB)were used.

The precipitate obtained presented the same structure as the materialsbased on nickel; only in this case, an ammonium complex resulted from amixed oxy-hydroxide of cobalt-molybdenum, (NH₄)HCO₂(OH)₂(MoO₄)₂. Theresulting material was sulfided directly through the sulfiding proceduredescribed in Example 1. The resulting sulfided material is made up of amixture of sulfided phases of the metallic components MoS₂,Co_(x)Mo_(y)S_(z), and CO₄S₃. For this example, the material in powderform (80:100 Tyler mesh) was sulfided directly and its catalyticactivity was determined in an autoclave reactor with a primary light gasoil (PLGO) diluted in hexadecane at 20% in volume, just as is describedin Example 1, only that in this case the operating pressure during thereaction was less (56 Kg/cm²). In this reaction, a product with 79 ppmin weight of sulfur was obtained after 6 h of reaction, and the reactionrate constant was 2.19*10⁻⁶ l/g·s.

Example 9

A material was prepared following the procedure described in Example 1.In order to do this, the same quantity of ammonium heptamolybdate (11.93g) was used, dividing the quantity of the second metal salt into two,10.6 g of nickel nitrate and 10.6 g of cobalt nitrate. The samemethodology was followed, obtaining a consistent precipitate of mixednitrate of cobalt, nickel, and molybdenum. The precipitate was washedand dried as in Example 1.

The solid obtained presented the mixed oxy-hydroxide structure ofnickel, cobalt, and molybdenum with ammonia such as:(NH₄)HCoNi(OH)₂(MoO₄)₂. The material with said structure was sulfideddirectly through the procedure described in Example 1, and its catalyticactivity in powder form (80:100 mesh) was evaluated in thehydrodesulfuration of a hydrocarbon fraction (PLGO), using a dilutedPLGO such as is described in Example 1. In this reaction a product with106 ppm of sulfur was obtained, with a reaction rate constant of1.84*10⁻⁶ L/g·s.

Example 10

For the purpose of observing the influence of the concentration of thesurface active agent added during the synthesis, in the two followingexamples the quantity of surface active agent incorporated was varied. Amaterial was prepared following the procedure described in Example 1,using the same quantities of precursor salts and of solvent; only thequantity of the surfactant added was varied, which was 1.65 g of CTAB.The precipitate was washed and dried as in Example 1.

The solid obtained presented the structure of a mixed oxy-hydroxide ofnickel, cobalt, and molybdenum with ammonia such as:(NH₄)HNi₂(OH)₂(MoO₄)₂. The material with said structure was sulfideddirectly through the procedure described in Example 1 and its catalyticactivity in powder form (80:100 Tyler mesh) was evaluated in the PLGOhydrodesulfuration, using a diluted PLGO such as is described inExample 1. The results are presented in Table 2. In this reaction, aproduct with 43 ppm of sulfur was obtained, with a reaction rateconstant of 3.02*10⁻⁶ L/g·s, slightly less than that observed forExample 1. However, it presented very high activity.

Example 11

Following the same procedure described in Example 1 and with the sameobjective as in Example 10, the quantity of surfactant was increased inthis example to 3.3 g of CTAB, using the same quantities of salts and ofsolvents as in Example 1.

The material obtained presented the same structure as that obtained inthe previous examples with the corresponding metals.

The resulting material was sulfided directly through the proceduredescribed in Example 1 and its catalytic activity in powder form (80:100Tyler mesh) was evaluated in the hydrodesulfuration of a hydrocarbonfraction (PLGO), using a diluted PLGO such as is described in Example 1.The results are presented in Table 2. In this reaction, a product with40 ppm of sulfur was obtained, with a reaction rate constant of3.08*10⁻⁶ L/g·s, slightly less than that observed for Example 1, andvery similar to the activity of the material synthesized in Example 10.By comparing the results obtained in the evaluation of the materialsprepared in Examples 1, 10, and 11, it can be deduced that the quantityof surface active agent does not influence the hydrodesulfuration speedin a significant manner, which is probably due to the fact that thesynthesis process includes a washing stage and only the organic compoundthat interacts strongly with the anions of the metals involved remainsin the solid, and the concentration of the anions does not vary with theincrease in the concentration of the surfactant.

Example 12

A catalytic composition was prepared in accordance with the proceduredescribed in Example 1. The precipitate obtained, nickel-molybdenumoxy-hydroxide, was mixed with a 20 wt. % of alumina boehmite, based onthe total weight of the catalytic composition. Afterward, an aqueoussolution of 3% weight of nitric acid dissolved in distilled water wasadded in such a way that a paste was obtained. The wet paste was left tostand in a closed container and then it was extruded. The resultingextrude was dried at 120° C. in accordance with the procedure describedin Example 1.

The extrudes were thermally treated in nitrogen atmosphere, at 400° C.,in order to achieve the elimination and possible carbonization of theorganic compound CTAB added during the mixture and reaction of thesolutions in the synthesis process. The resulting catalytic compositioncontains 16% weight of Al₂O₃, 55% weight of MoO₃, and 37% weight of NiO,and less than 1.5% of carbon. After the thermal treatment in inertatmosphere, the catalytic composition presented a specific area of 135m²/g, an average pore volume of 03 cm³/g, and an average pore diameterof 6 nm.

One part of this material was evaluated in a fixed bed plant andcontinuous flow operated at pressure, where 5 ml of the material (4.5 g)were packed in a reactor of 1.4 cm in diameter and 48 cm in length.Afterward, the catalysts were sulfided making a hydrocarbon fractionpass through (primary light gas oil, PLGO), whose characteristics arepresented in Table 3, to which dimethyl disulfide (DMDS) was added inorder to increase the content of S by 10 000 ppm. In this manner, thefinal total sulfur content is approx. 2.5 wt. % weight. The sulfidingwas carried out at a pressure of 27 kg/cm². The space velocity (LHSV)used for the sulfiding was 1.5 h⁻¹ and the H₂/hydrocarbon ratio of 333m³/m³. The catalytic bed temperature was increased from room temperatureto 135° C. at a rate of 40° C./h. Then, it was changed to 28° C./h up to343° C. and was stabilized for 3 h. Afterward, the system was carried atconditions of pressure, space velocity, and H₂/hydrocarbon ratio similarto the evaluation conditions (70 kg/cm², LHSV=2.5 h⁻¹, and 445 m³/m³)feeding the hydrocarbon feedstock to be hydrotreated (PLGO), and wasleft to stabilize for 96 h at 343° C. Then, the temperature was raisedto the first from the evaluation period (350° C.), operating in thismanner until the S content in the slurry (Antek analyzer and gaschromatograph with chemiluminescence detector) is considered essentiallyconstant. Once the aforementioned has been accomplished, the reactor iscarried to the next temperature to be evaluated.

TABLE 1 Catalytic activity in the DBT hydrodesulfuration reaction.(S_(CHF) + X_(DBT) S_(BF) S_(CHF) S_(BCH) S_(BCH))/ K Examples (mol %)(mol %) (mol %) (mol %) S_(BF) L/g · s 1 96 32.75 62.64 4.61 2.05 1.48 287 35.52 60.10 4.38 1.81 0.94 3 96 38.40 57.41 4.19 1.60 1.02 4 89 38.0658.70 3.24 1.63 0.75 5 97 89.04 10.60 0.36 0.12 1.02 6 98 79.07 20.500.43 0.26 1.27 7 97 90.57 9.43 0.0 0.10 1.12 (Commercial)

TABLE 2 Catalytic activity in the hydrodesulfuration reaction of a PLGOgas oil in a batch reactor. The initial sulfur concentration in thereaction mixture was 2688 ppm in weight. Content of S in productReaction Rate Constant Examples (wppm in weight) (K) * 10⁶ (L/g.s) 1 353.4 3 48 2.85 8 79 2.19 9 106 1.84 10 43 3.02 11 40 3.08

TABLE 3 Specification of the gas oil (PLGO) used for the catalyticactivity in the examples from this invention. Properties Result MethodSpecific Weight 0.8507 (g/mL) ASTM D-4052 Cetane Number 50 ASTM D-976Compounds Present Total Sulfur 14429 ppm weight Total Nitrogen 263 ppmweight Basic Nitrogen 107 ppm weight Total Aromatics 31.7% weightMonoaromatics 14.4% weight Dichromatics 12.8% weight Poliaromatics 4.5%weight Atmospheric Distillation Initial Boiling Temp. 214.8° C.  5%240.1 10% 251.6 15% 259.0 20% 265.2 30% 273.9 40% 282.4 50% 291.5 60%301.3 70% 312.9 80% 326.5 90% 344.2 95% 357.7 Final Boiling Temp. 376.5

TABLE 4 Catalytic activity in HDS of PLGO, of the catalyst prepared asis described in Example 12 and a commercial catalyst. S in productExample LHSV (h⁻¹) 330° C. 340 350 360 12 2.5 — 206 25 5 12 1.5  730 258 —  7 (comp.) 2.5 1146 760 428 —

The invention claimed is:
 1. A process for the preparation of acatalytic component consisting of at least one Group VIII non-noblemetal and a single Group VIB metal, the process comprising: the step ofreacting a solution of a soluble Group VIII metal precursor, a singlesoluble Group VIB metal precursor and a tetraalkyl quaternary ammoniumsalt at pH 5-14; evaporating the solution to form a crystallizedcomplex; thermally treating the crystallized complex; and sulfiding thethermally treated crystallized complex to obtain the catalyticcomponent.
 2. The process of claim 1, wherein said quaternary ammoniumsalt is a salt of a tetraalkyl ammonium ion having the formula NR₄ ⁺where R is an alkyl.
 3. The process of claim 2, wherein each R isindependently a C₁ to C₈ alkyl group.
 4. The process of claim 3, whereineach R is independently a C₁ to C₈ alkyl substituted in a halogen orhydroxyl group.
 5. The process of claim 2, wherein said quaternaryammonium salt is a salt of a tetraalkyl ammonium ion having the formulaR′NR₃ ⁺ where R′ is a C₁₂ to C₂₀ alkyl group and each R is independentlya C₁ to C₈ alkyl group.
 6. A process of preparing a catalytic component,the process comprising: a) forming a solution and mixture of precursorsalts in a solvent selected from the group consisting of water,methanol, ethanol, propanol, butanol, and mixtures thereof, saidprecursor salt being salts of at least one Group VIII non-noble metaland a single Group VIB metal; b) forming a solution of a tetraalkylquaternary ammonium salt in a solvent; c) forming a mixture of thesolutions obtained in steps (a) and (b); d) adding a basic hydroxidesolution and/or ammonium carbonate to the solution (c) at a pH comprisedbetween 5 and 14; e) heating the solution obtained in step (d) to atemperature between 50 and 200° C.; f) homogenizing the solution in step(e); g) crystallizing the solution obtained in step (f) throughevaporation of the solvent; h) filtering or centrifugation of theresulting crystallized suspension obtained in step (g) for theseparation of the crystals and recovery of mother liquors in the eventthat the evaporation has not been completed; i) washing the solidobtained in step (h) with sufficient deionized water and/orwater/alcohol mixture; j) drying the solid obtained in step (i) at atemperature between 50 and 300° C.; k) thermally treating the solidobtained in step (j) in inert atmosphere of nitrogen, helium, or argon,at a temperature between 200 and 1000° C.; l) sulfiding of the materialobtained step (i) or in step (j) in a gaseous flow made up of 10 vol. %hydrogen sulfide or with a hydrocarbon fraction containing at least 0.2wt. % sulfur with a hydrogen flow at a temperature between 200 and 600°C., and a pressure between 1 and 100 Kg/cm² to obtain said catalyticcomponent consisting essentially of at least one Group VIII non-noblemetal and a single Group VIB metal.
 7. The preparation process inaccordance with claim 6, in which the at least one Group VIII non-noblemetal and a single Group VIB metal precursor salts are completelydissolved in a liquid used as solvent.
 8. The preparation process inaccordance with claim 7, in which the completely dissolved precursorsalts are mixed with a solution that contains a surface active compound.9. The preparation process in accordance with claim 6, where the solventused comprises water and/or alcohol and/or alcohol-water mixture. 10.The preparation process in accordance with claim 6, where the quaternaryammonium salt (R₄N⁺) is chloride, bromide, fluoride, or hydroxide. 11.The preparation process in accordance with claim 6, where the Group VIIInon-noble metal includes nickel, cobalt, and/or iron, or a mixture ofthese metals.
 12. The preparation process in accordance with claim 11,where the nickel and/or cobalt represent 100 wt. % of the Group VIIInon-noble metals calculated as oxides.
 13. The preparation process inaccordance with claim 6, where the Group VIB metal is one selected fromthe group consisting of molybdenum, tungsten and chromium.
 14. Thepreparation process in accordance with claim 6, where the homogenizationstep of the solutions takes place at a temperature and at a pH such thatall the selected precursor salts are in a completely soluble state. 15.The preparation process in accordance with claim 6, where thehomogenization step of the solutions takes place at a time between 5 minand 24 h.
 16. The preparation process in accordance with claim 6, wherethe solution's crystallization step is carried out by partialevaporation of the solvent in a crystallizer and/or by total evaporationof the solvent in an evaporator.
 17. The preparation process inaccordance with claim 6, where the solution's crystallization step iscarried out by evaporation of the solvent at a temperature between 80and 200° C.
 18. The preparation process in accordance with claim 6,where the thermal treatment in inert atmosphere stage is carried out ata temperature between 300 and 600° C., in a flow of nitrogen, helium,argon, or mixtures thereof at a flow of at least 0.01 L/g·min.
 19. Thepreparation process in accordance with claim 6, where the thermaltreatment is not be carried out in oxidizing atmosphere.
 20. Thepreparation process in accordance with claim 6, where the sulfiding stepis carried out either on the dry or thermally treated material in thepresence of a liquid fraction of hydrocarbons that contains at least 0.1wt. % of sulfur and hydrogen at pressures comprised between 1 and 100Kg/cm², at temperatures between 200 and 600° C.
 21. The preparationprocess in accordance with claim 6 including an inorganic oxide binderselected from the group consisting of alumina, silica, titania,silica-alumina, alumina-titania, zirconia, zirconia-titania,zirconia-alumina, amorphous silico-aluminates, and/or crystalline claysin the homogenization step of the mixture of precursor salts.
 22. Thepreparation process in accordance with claim 6, further comprising theaddition of an inorganic oxide binder, after the crystallization stagein the wet and/or dry material.
 23. The preparation process inaccordance with claim 6, further comprising the addition of an inorganicoxide as a binder, after the material has been thermally treated and/orsulfided.
 24. The preparation process in accordance with claim 6,further comprising extruding the material containing an inorganic oxideas a binder.
 25. The process of claim 6, wherein said tetraalkylammonium salt is a salt of a tetraalkyl ammonium cation having theformula NR₄ ⁺ where R is independently a C₁ to C₈ alkyl group.
 26. Theprocess of claim 25, wherein R is a substituted alkyl containing ahalogen or hydroxy group.
 27. The process of claim 6, wherein saidtetraalkyl ammonium salt is a salt of a tetraalkyl ammonium cationhaving the formula R′NR₃ ⁺ where R′ is a C₁₂ to C₂₀ alkyl group and R isindependently a C₁ to C₈ alkyl group.
 28. A process for producing acatalytic composition comprising the steps of: forming a first solutionof a soluble Group VIII non-noble metal precursor and only one Group VIBmetal precursor; forming a second solution containing a componentselected from the group consisting of an ionic surfactant and atetraalkyl quaternary ammonium salt, and mixing with said first solutionof said Group VIII and Group VIB precursors; removing said solvent andcrystallizing the resulting solid product; thermally treating theresulting solid product in an inert atmosphere at a temperature of 200°C. to 1000° C. to obtain a heat-treated product; and sulfiding theheat-treated product to obtain the catalytic composition comprising acatalytic component consisting essentially of a Group VIII non-noblemetal and one Group VIB metal.
 29. The process of claim 28, wherein saidsecond solution is a solution of said tetraalkyl quaternary ammoniumsalt of a tetraalkyl quaternary ammonium ion having the formula NR₄ ⁺where R is independently a C₁ to C₈ alkyl group.
 30. The process ofclaim 28, wherein said second solution is a solution of a tetraalkylquaternary ammonium salt of a tetraalkyl quaternary ammonium having theformula R′NR₃ ⁺ where R′ is a C₁₂ to C₂₀ alkyl group and R isindependently a C₁ to C₈ alkyl group.
 31. The process of claim 28,wherein said solution is a solution of a cationic, anionic or neutralsurfactant.